﻿/* 
 * PROJECT: NyARToolkitCS
 * --------------------------------------------------------------------------------
 *
 * The NyARToolkitCS is C# edition NyARToolKit class library.
 * Copyright (C)2008-2012 Ryo Iizuka
 *
 * This work is based on the ARToolKit developed by
 *   Hirokazu Kato
 *   Mark Billinghurst
 *   HITLab, University of Washington, Seattle
 * http://www.hitl.washington.edu/artoolkit/
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as publishe
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * For further information please contact.
 *	http://nyatla.jp/nyatoolkit/
 *	<airmail(at)ebony.plala.or.jp> or <nyatla(at)nyatla.jp>
 * 
 */
namespace jp.nyatla.nyartoolkit.cs.core
{


    /**
     * このクラスは、遠近法を用いてPerspectiveパラメータを計算します。
     * 遠近法を可読性を重視して実装している為、若干低速です。
     * 高速化をした{@link NyARPerspectiveParamGenerator_O1}関数を使用してください。
     */
    public class NyARPerspectiveParamGenerator_Reference : NyARPerspectiveParamGenerator
    {
        /**
         * コンストラクタです。
         * @param i_local_x
         * パラメータ計算の基準点を指定します。
         * @param i_local_y
         * パラメータ計算の基準点を指定します。
         */
        public NyARPerspectiveParamGenerator_Reference(int i_local_x, int i_local_y)
            : base(i_local_x, i_local_y)
        {
            return;
        }

        /**
         * この関数は、遠近法のパラメータを計算して、返却します。
         */
        public sealed override bool getParam(int i_dest_w, int i_dest_h, double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4, double[] o_param)
        {
            double ltx = this._local_x;
            double lty = this._local_y;
            double rbx = ltx + i_dest_w;
            double rby = lty + i_dest_h;

            NyARDoubleMatrix44 mat_x = new NyARDoubleMatrix44();
            mat_x.m00 = ltx; mat_x.m01 = lty; mat_x.m02 = -ltx * x1; mat_x.m03 = -lty * x1;
            mat_x.m10 = rbx; mat_x.m11 = lty; mat_x.m12 = -rbx * x2; mat_x.m13 = -lty * x2;
            mat_x.m20 = rbx; mat_x.m21 = rby; mat_x.m22 = -rbx * x3; mat_x.m23 = -rby * x3;
            mat_x.m30 = ltx; mat_x.m31 = rby; mat_x.m32 = -ltx * x4; mat_x.m33 = -rby * x4;
            mat_x.inverse(mat_x);
            NyARDoubleMatrix44 mat_y = new NyARDoubleMatrix44();
            mat_y.m00 = ltx; mat_y.m01 = lty; mat_y.m02 = -ltx * y1; mat_y.m03 = -lty * y1;
            mat_y.m10 = rbx; mat_y.m11 = lty; mat_y.m12 = -rbx * y2; mat_y.m13 = -lty * y2;
            mat_y.m20 = rbx; mat_y.m21 = rby; mat_y.m22 = -rbx * y3; mat_y.m23 = -rby * y3;
            mat_y.m30 = ltx; mat_y.m31 = rby; mat_y.m32 = -ltx * y4; mat_y.m33 = -rby * y4;
            mat_y.inverse(mat_y);
            double a = mat_x.m20 * x1 + mat_x.m21 * x2 + mat_x.m22 * x3 + mat_x.m23 * x4;
            double b = mat_x.m20 + mat_x.m21 + mat_x.m22 + mat_x.m23;
            double d = mat_x.m30 * x1 + mat_x.m31 * x2 + mat_x.m32 * x3 + mat_x.m33 * x4;
            double f = mat_x.m30 + mat_x.m31 + mat_x.m32 + mat_x.m33;

            double g = mat_y.m20 * y1 + mat_y.m21 * y2 + mat_y.m22 * y3 + mat_y.m23 * y4;
            double h = mat_y.m20 + mat_y.m21 + mat_y.m22 + mat_y.m23;
            double i = mat_y.m30 * y1 + mat_y.m31 * y2 + mat_y.m32 * y3 + mat_y.m33 * y4;
            double j = mat_y.m30 + mat_y.m31 + mat_y.m32 + mat_y.m33;

            NyARDoubleMatrix22 tm = new NyARDoubleMatrix22();
            tm.m00 = b;
            tm.m01 = -h;
            tm.m10 = f;
            tm.m11 = -j;
            tm.inverse(tm);


            double A, B, C, D, E, F, G, H;

            C = tm.m00 * (a - g) + tm.m01 * (d - i);	//C
            F = tm.m10 * (a - g) + tm.m11 * (d - i);	//F
            G = a - C * b;
            H = d - C * f;
            A = (mat_x.m00 * x1 + mat_x.m01 * x2 + mat_x.m02 * x3 + mat_x.m03 * x4) - C * (mat_x.m00 + mat_x.m01 + mat_x.m02 + mat_x.m03);
            B = (mat_x.m10 * x1 + mat_x.m11 * x2 + mat_x.m12 * x3 + mat_x.m13 * x4) - C * (mat_x.m10 + mat_x.m11 + mat_x.m12 + mat_x.m13);
            D = (mat_y.m00 * y1 + mat_y.m01 * y2 + mat_y.m02 * y3 + mat_y.m03 * y4) - F * (mat_y.m00 + mat_y.m01 + mat_y.m02 + mat_y.m03);
            E = (mat_y.m10 * y1 + mat_y.m11 * y2 + mat_y.m12 * y3 + mat_y.m13 * y4) - F * (mat_y.m10 + mat_y.m11 + mat_y.m12 + mat_y.m13);

            o_param[0] = A;
            o_param[1] = B;
            o_param[2] = C;
            o_param[3] = D;
            o_param[4] = E;
            o_param[5] = F;
            o_param[6] = G;
            o_param[7] = H;


            return true;

        }
    }
}
